JP2005030502A - Electromagnetic driving unit and solenoid valve device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electromagnetic driving unit for generating stable driving force and switched to miniaturization, and to provide a solenoid valve device using the same and capable of stably working over a long time without unevenness of characteristic and switched to miniaturization. <P>SOLUTION: This electromagnetic driving unit has a fixed iron core, a movable iron core 72 slidably arranged on the same shaft with the fixed iron core and formed with an oil chamber, to which lubricating oil is supplied, in both sides thereof, and a solenoid surrounding the movable iron core 72. This electromagnetic driving unit is also provided with a solenoid assembly for operating the movable iron core 72 by controlling power supply to the solenoid, a non-magnetic resin layer 74 covering the peripheral surface of the movable iron core 72, grooves 76 and 76 formed in the resin layer 74 to communicate the oil chambers provided in both sides of the movable iron core 72 with each other, and an operating rod fitted by pressing into the movable iron core 72 to integrally move with the movable iron core 72. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an electromagnetic drive unit having a solenoid assembly and an electromagnetic valve device.

An electromagnetic drive unit and an electromagnetic valve device using the same are disclosed in, for example, Patent Document 1.
This electromagnetic drive unit has a fixed iron core and a movable iron core arranged on the same axis, and the movable iron core approaches or separates from the fixed iron core by the excitation force of the solenoid that surrounds the outside, that is, the power supply control of the solenoid. Is possible. A shaft is inserted into the movable iron core concentrically, and the tip of the shaft is formed as a valve body that opens and closes the valve opening of the electromagnetic valve device. The tip of the shaft, that is, its valve body, adjusts the opening degree of the valve opening and the flow rate is proportionally controlled by the moving iron core. In addition, the movable iron core is formed with through holes that open at both end faces and extend along the shaft. The through holes communicate oil chambers defined on both sides of the movable iron core so that the movable iron core is connected to and separated from the movable iron core. At this time, the flow of the lubricating oil between the oil chambers is allowed through the through hole.

According to this solenoid valve device, since the contact and separation of the movable iron core is directly transmitted to the shaft, the characteristics of the spring itself are more uneven and deteriorated over time than when the operation of the movable iron core is transmitted to the shaft via the spring. It is considered that the variation and deterioration of the characteristics of the electromagnetic valve device due to the above can be prevented.
JP 2002-151327 A (FIG. 1 and the like)

  By the way, in recent years, miniaturization is required for the electromagnetic drive unit and the solenoid valve device, and the diameter of the movable iron core is also desired to be reduced. However, in the electromagnetic drive unit disclosed in Patent Document 1, there is a limit to reducing the diameter of the movable iron core due to the presence of the through hole, and if the diameter is forcibly reduced, the portion around the through hole becomes thin. When the shaft is press-fitted into the movable iron core, the movable iron core is distorted, the outer diameter of the movable iron core is not uniform in the circumferential direction, and the smooth sliding of the movable iron core is impaired, and the magnetic characteristics are also reduced. The characteristics of the electromagnetic drive unit are deteriorated, for example, the shaft driving force is reduced.

  The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to generate a stable driving force and to be suitable for miniaturization, and there is little variation in characteristics using the electromagnetic driving unit. Another object of the present invention is to provide a solenoid valve device that operates stably over a long period of time and is suitable for downsizing.

  The electromagnetic drive unit of the present invention includes a fixed iron core, a movable iron core that is slidably arranged coaxially with respect to the fixed iron core, and that divides oil chambers to which lubricating oil is supplied at both ends, A solenoid that surrounds the movable iron core, and is formed on the resin layer, a solenoid assembly that operates the movable iron core by power supply control to the solenoid, a nonmagnetic resin layer that covers an outer peripheral surface of the movable iron core, and A groove that communicates between the oil chambers on both sides of the movable iron core, and an operation rod that is press-fitted into the movable iron core and moves integrally with the movable iron core (Claim 1).

According to the electromagnetic drive unit having the above-described structure, the resin layer covering the outer peripheral surface of the movable iron core is provided with the grooves that allow the oil chambers on both sides of the movable iron core to communicate with each other. There is no need to pierce the movable iron core with an oil passage composed of a groove and a groove, so that the movable iron core can be downsized, and the electromagnetic drive unit itself can be downsized.
Furthermore, since there is no need to form an oil passage in the movable iron core itself, the thickness of the movable iron core is uniform over the entire circumference, and even if the operating rod is pressed into the movable iron core and attached, the movable iron core is distorted. It does not occur. Therefore, even if the operating rod is press-fitted, the outer diameter of the movable iron core is maintained uniformly over the entire circumference, and this electromagnetic drive unit generates a stable drive force.

And it is preferable that the said resin layer further contains the circumferential groove | channel along the circumferential direction of the said movable iron core (Claim 2). The circumferential groove allows lubricating oil to flow along the circumferential direction of the movable iron core, so that the movable iron core is positioned accurately concentrically with respect to the solenoid. As a result, the electromagnetic drive unit has a more stable driving force. appear.
Further, if the groove is formed by applying a resin material to the outer peripheral surface of the movable core that has been masked (Claim 3), the groove can be easily formed on the outer peripheral surface of the movable core, and an electromagnetic drive unit is provided. It can be easily downsized.

The electromagnetic valve device of the present invention includes the above-described electromagnetic drive unit, and a valve that has a valve body that is operated by the operation rod, and that is switched in response to the operation of the movable iron core. 4).
According to the electromagnetic valve device having the above-described configuration, the resin layer covering the outer peripheral surface of the movable iron core is provided with the grooves that allow the oil chambers on both sides of the movable iron core to communicate with each other. There is no need to drill an oil passage composed of a groove or the like in the movable iron core, the movable iron core and the electromagnetic drive unit can be downsized, and the solenoid valve device itself can be downsized. In addition, since the valve element is operated by the operation rod, this electromagnetic valve device operates stably over a long period of time with little variation in characteristics.

1 and 2 are longitudinal sectional views of an electromagnetic valve device 10 (hereinafter referred to as electromagnetic valve 10) according to an embodiment of the present invention. The solenoid valve 10 is a three-port two-position directional control valve that operates in an electromagnetically operated manner. FIG. 1 shows the solenoid valve 10 in one of these two positions, and FIG. 2 shows the other supply position. A certain solenoid valve 10 is shown.
The solenoid valve 10 is used for various controls, such as mini-excavator cabin interference prevention / depth control, hydraulic piston / motor tilt point angle control, control valve spool / throttle valve control, AT car clutch pack, Suitable for forward / reverse switching clutch control and the like.

The electromagnetic valve 10 includes a valve unit 12 and an electromagnetic drive unit 14 that is mechanically connected to one end side of the valve unit 12 and switches the valve unit 12 to operate.
The drive unit 14 includes a bottomed cylindrical solenoid housing 16 (hereinafter referred to as a housing 16). The housing 16 includes an outer peripheral wall 18 and an end wall 20 located on one end side of the outer peripheral wall 18. A valve unit 12 is connected to 20. Further, a fixed iron core 22 is integrally formed at the center of the end wall 20.

The fixed iron core 22 has a cylindrical shape, protrudes inward of the housing 16 from the end wall 20, and is positioned concentrically with the outer peripheral wall 18. Therefore, the fixed iron core 22 and the outer peripheral wall 18 are separated from each other by a predetermined width as viewed in the radial direction thereof.
A rod hole 24 is formed concentrically at the center of the fixed core 22, and both ends of the rod hole 24 open on the inner and outer surfaces of the end wall 20, that is, on the outer end surface and the inner end surface 26 of the fixed core 22. The fixed iron core 22 includes an annular protruding edge 28 that protrudes integrally from the peripheral edge of the inner end surface 26 in the axial direction.

The annular projecting edge 28 has a constant inner diameter along the axial direction of the fixed iron core 22, but its outer diameter gradually decreases toward the tip. Therefore, the tip outer shape of the annular projecting edge 28 has a truncated cone shape. A non-magnetic annular spacer 32 is disposed on the inner end face 26 of the fixed iron core 22, and the inside of the annular projecting edge 28 communicates with the rod hole 24 through the spacer 32.
A cylindrical solenoid assembly 34 is concentrically accommodated in the housing 16. The solenoid assembly 34 is a bobbin 36, a solenoid 38 wound around the bobbin 36, and a bobbin 36 that is externally fitted to the solenoid. A bobbin cover covering 38 is included.

More specifically, one end portion of the solenoid assembly 34 is fitted between the fixed iron core 22 and the outer peripheral wall 18, and one end surface thereof is in contact with the end wall 20 via an O-ring. The O-ring provides a fluid tight seal between one end of the solenoid assembly 34 and the end wall 20.
The solenoid assembly 34 (bobbin 36) has a stepped inner peripheral surface. The inner peripheral surface is a small-diameter portion 40 located in the center in the axial direction, and two large-diameter portions 42, 44 sandwiching the small-diameter portion 40. And a tapered portion 46 interposed between the small-diameter portion 40 and the large-diameter portion 42, and the tapered portion 46 is positioned so as to form a constant gap with the tip of the annular projecting edge 28 of the fixed iron core 22. ing. The inner diameter of the small diameter portion 40 of the bobbin 36 is slightly larger than the inner diameter of the annular projecting edge 28.

The other end of the solenoid assembly 34 (bobbin cover) is located in the vicinity of the opening end of the housing 16, and a yoke 48 is coaxially connected to the other end, and one end of the yoke 48 is the solenoid assembly 34. The open end of the outer peripheral wall 18 is closed in a state of being fitted inside.
More specifically, the yoke 48 includes a cylindrical portion 50 and a flange portion 52 that are integrally formed with each other. The cylindrical portion 50 has a bottomed cylindrical shape, and has a concentric hole 54 opened at one end and closed at the other end. Further, the flange portion 52 is positioned in the middle of the cylindrical portion 50 when viewed in the axial direction, the flange portion 52 is positioned in the opening end of the housing 16, and the opening edge of the housing 16 with respect to the outer edge portion thereof. By crimping, the opening end of the housing 16 is closed.

The other end (bottom) side of the cylindrical portion 50 protrudes outward from the housing 16, and one end (opening) side of the cylindrical portion 50 is inserted into the solenoid assembly 34, that is, the stepped large diameter portion 44 of the bobbin 36 via an O-ring. It is inserted.
A through hole (not shown) is formed in the collar portion 52, and an electrically insulating sleeve 56 is fitted into the through hole. A pair of connection terminals 58 penetrates the flange portion 52 through the sleeve 56, and one end of the connection terminals 58 is electrically connected to the solenoid 38.

An electrically insulating cover 60 is molded and disposed on the outer surface of the flange portion 52, and the cover 60 is not only the outer surface of the flange portion 52 but also the crimped opening edge of the housing 16, the sleeve 56, and the sleeve 56. A part of the connection terminal 58 extending outward and a part of the cylindrical portion 50 are embedded.
Here, a peripheral wall 62 surrounding the connection terminal 58 in an exposed state is provided on a part of the cover 60, and the peripheral wall 62 constitutes a male plug together with the connection terminal 58. Therefore, power can be supplied from the outside of the housing 16 to the solenoid 38 by inserting the male plug and a female plug (not shown).

The concentric hole 54 of the yoke 48 has an inner diameter equal to the inner diameter of the annular protruding edge 28 of the fixed iron core 22, and a small-diameter hole 64 extending in the axial direction at the center is formed on the inner bottom surface of the concentric hole 54. Has been.
A circular spring seat 66 is disposed in contact with the inner bottom surface of the concentric hole 54, and the spring seat 66 has a convex portion 68 fitted into the hole 64 on the inner bottom surface. Further, the spring seat 66 has a bottomed hole concentric with the concentric hole 54 on the end surface opposite to the convex portion 68.

Here, the concentric hole 54 in which the spring seat 66 is accommodated forms an accommodation chamber 70 together with the inner peripheral surface of the solenoid assembly 34 and the annular protruding edge 28 of the fixed iron core 22, and this accommodation chamber 70 is a rod of the fixed iron core 22. It is positioned coaxially with the hole 24 and communicates with the rod hole 24.
A cylindrical movable iron core 72 is accommodated in the accommodation chamber 70. As shown in FIG. 3, the outer peripheral surface of the movable iron core 72 is covered with a resin layer 74 having a uniform thickness, and the outer peripheral surface of the resin layer 74 has two axial grooves 76 and 76 at axially symmetrical positions. Is formed. Each axial groove 76, 76 opens at both end faces of the movable iron core 72, and communicates the oil chambers 78, 80 on both sides of the movable iron core 72 with each other. The oil chamber 78 (see FIG. 1) is defined between one end surface of the movable iron core 72 and the fixed iron core 22, and the oil chamber 80 (see FIG. 2) is located between the other end surface of the movable iron core 72 and the spring seat 66. It is divided into.

The movable iron core 72 is slidably guided to the concentric hole 54 of the yoke 48 and the inner peripheral surface 30 of the annular protruding edge 28 of the fixed iron core 22 through the resin layer 74.
In this embodiment, the outer diameter of the movable iron core 72 not including the resin layer 74 is 10 mm, the resin layer 74 is made of a nylon resin, and the thickness thereof is 0.18 mm. The width of each axial groove 76 is 6 mm, and the clearance between the resin layer 74 and the concentric hole 54 is 20 to 40 μm.

  This resin layer 74 can be formed by a known method. For example, a mask is applied to the outer peripheral surface of the movable iron core 72 where the axial grooves 76 and 76 are to be formed, and then the resin layer 74 is uniformly formed on the outer peripheral surface. The axial grooves 76 and 76 can be easily formed by removing the mask after applying and curing the resin material with a film thickness. Moreover, although the material and thickness of the resin layer 74 are not limited to what was mentioned above, it is preferable that the thickness is contained in the range of 0.1-0.2 mm. This is because when the thickness is less than 0.1 mm, the durability of the resin layer 74 is poor, and conversely, when the thickness exceeds 0.2 mm, the sliding resistance increases due to the deformation of the resin layer 74.

  Referring to FIGS. 1 and 2 again, the movable iron core 72 has concentric axial holes 82 that open at both end faces thereof. One end of a cylindrical rod 84 is press-fitted concentrically into the axial hole 82 from the end surface on the fixed iron core 22 side to the middle thereof, and the movable iron core 72 and the rod 84 are paired with each other. Yes. The rod 84 has an outer diameter slightly smaller than the inner diameter of the rod hole 24, extends from the movable iron core 72 through the spacer 32 and the rod hole 24, and the tip of the rod 84 contacts the end surface of the valve spool 90 of the valve unit 12 described above. Touching.

Here, the press-fit end of the rod 84 forms an inner end face 86 in the axial hole 82, and a coiled spring 88 is interposed between the inner end face 86 and the spring seat 66. Urges the movable iron core 72 forward (fixed iron core 22).
The valve unit 12 has a sleeve 92 in which a valve spool 90 is slidably received, and the sleeve 92 is screwed and connected to the end wall 20 of the housing 16 in the drive unit 14. More specifically, a female screw portion 94 projects from the outer surface of the end wall 20, while the sleeve 92 has a male screw portion 96 that engages with the female screw portion 94.

  Thus, one end of the sleeve 92 is closed by the end wall 20, and the other end opposite to the end wall 20 (male screw portion 96) is closed by the end plate 98. A valve spring 100 made of a compression coil spring is disposed between the end plate 98 and the valve spool 90. The valve spring 100 presses and biases the valve spool 90 toward the drive unit 14, and the valve spool 90 is The rod 84 is always kept in contact with the rod 84.

  The sleeve 92 has three ports that are axially spaced from each other, that is, a supply port 102 connected to the pump, an output port 104 connected to the actuator, and a tank port 106 connected to the tank. Inter-connection between the port 104 and between the output port 104 and the tank port 106 is controlled by the land portions 108 and 110 of the valve spool 90.

  These land portions 108, 110 form two annular chambers 112, 114 in the sleeve 92. The annular chamber 112 is always in communication with the supply port 102, and the annular chamber 114 is always in communication with the tank port 106. As shown in FIG. 1, when the valve spool 90 moves to the end wall 20 side (discharge position), the output port 104 and the tank port 106 communicate with each other via the annular chamber 114, while the land portion Reference numeral 108 indicates a supply flow path from the supply port 102 through the annular chamber 112 to the output port 104, that is, communication between the annular chamber 112 and the output port 104 is blocked. On the other hand, as shown in FIG. 2, when the valve spool 90 moves to the end plate 98 side (supply position) against the pressing biasing force of the valve spring 100, the land portion 108 has the annular chamber 112 (supply port 102). ) And the output port 104, while the land portion 110 blocks communication between the output port 104 and the annular chamber 114.

  The valve spool 90 is provided with an internal passage, and both ends of the internal passage open toward the end surface of the valve spool 90 on the rod 84 side and the annular chamber 114, respectively. Accordingly, a part of the oil in the annular chamber 114 can be supplied as lubricating oil to the accommodation chamber 70 of the drive unit 14, that is, the oil chambers 78 and 80 through the internal passage, the rod hole 24 and the spacer 32.

Hereinafter, the operation of the electromagnetic valve 10 described above when applied to the hydraulic control of the actuator will be described.
In operating the solenoid valve 10, first, the solenoid valve 10 is connected to a power source. This power supply may be either a DC power supply or an AC power supply. For example, DC12V or DC24V can be used as the DC power supply, and AC100V (50/60 Hz) or AC200V can be used as the AC power supply.

When the solenoid 38 is not energized, as shown in FIG. 1, the valve spool 90 is biased by the valve spring 100 and positioned at the discharge position, while the movable iron core 72 resists the biasing force of the spring 88. It is positioned at a position (non-operating position) separated from the fixed iron core 22 until it abuts against the seat 66.
Thus, when the solenoid valve 10 is in the discharge position, the supply port 102 and the output port 104 are blocked, so that the hydraulic oil is not supplied from the pump to the actuator, and the hydraulic oil in the actuator is not supplied. It flows to the tank through the output port 104, the annular chamber 114, and the tank port 106, and the actuator is deactivated. At this time, part of the hydraulic oil is also supplied as lubricating oil into the storage chamber 70 through the internal passage of the valve spool 90, the rod hole 24, and the spacer 32 as described above.

  When power is supplied from the power source to the solenoid 38 via the connection terminal 58, a magnetic field (excitation force) is generated by the solenoid 38, and the movable iron core 72 is attracted to the fixed iron core 22 with a suction force corresponding to the amount of current. At this time, since the outer peripheral surface of the movable iron core 72 is guided to the inner peripheral surface of the concentric hole 54 and the inner peripheral surface 30 of the annular projecting edge 28 via the resin layer 74, it is coaxial with the fixed core 22. Is displaced toward the fixed iron core 22 while being held in contact with the nonmagnetic spacer 32. The spacer 32 prevents the movable iron core 72 from coming into direct contact with the fixed iron core 22. The displacement of the movable iron core 72 is transmitted to the valve spool 90 via the rod 84, the valve spring 100 is compressed as shown in FIG. 2, and the valve spool 90 is positioned at the supply position. That is, the rod 84 functions as a pressing member that directly transmits the displacement of the movable iron core 72 to the valve spool 90.

  At this time, the lubricating oil in the oil chamber 78 on the fixed iron core 22 side flows into the oil chamber 80 on the spring seat 66 side through the axial groove 76 of the resin layer 74 covering the movable iron core 72. Such movement of the lubricating oil from the oil chamber 78 to the oil chamber 80 ensures a smooth displacement of the movable iron core 72, and the lubricating oil in the oil chamber 78 is a damper that alleviates the rapid operation of the movable iron core 72. Function as. At this time, part of the lubricating oil in the oil chamber 78 is also discharged to the valve unit 12 side through the gap between the inner peripheral surface of the rod hole 24 and the rod 84.

Thus, when the valve spool 90 moves to the supply position, the supply port 102 and the output port 104 communicate with each other to supply hydraulic oil from the pump to the actuator, while the output port 104 and the tank port 106 communicate with each other. Blocked. Accordingly, the actuator is actuated upon receiving the hydraulic oil.
When the power supply to the solenoid 38 is stopped, the magnetic field generated by the solenoid 38 disappears, the valve spool 90 is positioned at the discharge position by the extension force of the valve spring 100 compressed previously, and the movable core 72 is also fixed to the fixed core 22. Return to the original non-actuated position. Also at this time, the movable iron core 72 is guided to the inner peripheral surface of the concentric hole 54 and the inner peripheral surface 30 of the annular projecting edge 28 through the resin layer 74 and returns to the inoperative position. At this time, the lubricating oil flows from the oil chamber 80 on the spring seat 66 side into the oil chamber 78 on the fixed iron core 22 side through the axial groove 76 of the resin layer 74 covering the movable iron core 72, and the movable iron core 72 is smoothly displaced. Guarantee. In this case, the lubricating oil in the oil chamber 80 functions as a damper when switching from the supply position to the discharge position.

  In the case of the drive unit 14 described above, the resin layer 74 covering the outer peripheral surface of the movable core 72 is provided with the axial grooves 76 that allow the oil chambers 78 and 80 on both sides of the movable core 72 to communicate with each other. Therefore, it is not necessary to drill an oil passage composed of a through hole, a groove, or the like in the movable iron core 72 along the axial hole 82, and the movable iron core 72 can be downsized, and the drive unit 14 itself can be downsized. Is possible.

  Furthermore, since it is not necessary to form an oil passage in the movable iron core 72 itself, the thickness of the movable iron core 72 is uniform over the entire circumference, and the rod 84 is press-fitted and attached to the axial hole 82 of the movable iron core. However, the movable iron core 72 is not distorted, and even when the rod 84 is press-fitted, the outer diameter of the movable iron core 72 is maintained uniformly over the entire circumference. Therefore, the movable iron core 72 can slide while maintaining a coaxial relationship with the fixed iron core 22 with a low sliding resistance, and variations in the exciting force and the sliding resistance actually acting on the movable iron core 72 are small. As a result, the driving unit 14 generates a stable driving force.

  And in the case of the electromagnetic valve 10 provided with the drive unit 14, since the displacement of the movable iron core 72 is transmitted to the valve spool 90 via the rod 84 as a pressing member, the electromagnetic using a spring as the pressing member as described above. Compared with the valve, the electromagnetic valve 10 has less variation in characteristics among products and has a long life. And since the movable iron core 72 and the drive unit 14 are suitable for size reduction, size reduction of the solenoid valve 10 is also possible. Further, since the drive unit 14 generates a stable driving force, the solenoid valve 10 can be stably switched.

Furthermore, the resin layer 74 having the axial groove 76 can be easily formed on the outer peripheral surface of the movable iron core 72, and the drive unit 14 and the electromagnetic valve 10 can be easily downsized.
The present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the number of ports and the number of switching positions of the electromagnetic valve 10 are not limited to the above-described embodiment.
In the above-described embodiment, the two axial grooves 76 and 76 are formed on the outer peripheral surface of the movable iron core 72. In addition to this, as illustrated in FIG. Directional grooves 116 may be formed. These circumferential grooves 116 can position the movable iron core 72 accurately and concentrically with the solenoid 38 by flowing lubricating oil along the circumferential direction of the movable iron core 72. Furthermore, since these circumferential grooves 116 reduce the contact area between the movable iron core 72 and the accommodating chamber 70 in addition to flowing lubricating oil, the sliding resistance of the movable iron core 72 can be further reduced. .
Further, as illustrated in FIG. 5, the spiral groove 118 may be provided on the outer peripheral surface of the movable iron core 72.

<Effect of the invention>
According to the electromagnetic drive unit of the present invention, since the resin layer covering the outer peripheral surface of the movable iron core is provided with the grooves that allow the oil chambers on both sides of the movable iron core to communicate with each other, There is no need to drill an oil passage composed of a groove or the like in the movable iron core, the movable iron core can be miniaturized, and the electromagnetic drive unit itself can be miniaturized.

Furthermore, since there is no need to form an oil passage in the movable iron core itself, the thickness of the movable iron core is uniform over the entire circumference, and even if the operating rod is pressed into the movable iron core and attached, the movable iron core is distorted. It does not occur. Therefore, even if the operating rod is press-fitted, the outer diameter of the movable iron core is maintained uniformly over the entire circumference, and this electromagnetic drive unit generates a stable drive force (claim 1).
Further, when the electromagnetic drive unit of the present invention further includes a circumferential groove along the circumferential direction of the movable iron core, the circumferential groove causes the lubricating oil to flow along the circumferential direction of the movable iron core, thereby The movable iron core is positioned precisely concentrically, and as a result, a more stable driving force is generated (claim 2).

According to the electromagnetic drive unit of the present invention, when the groove for connecting the oil chambers to each other is formed by applying a resin material on the outer peripheral surface of the masked movable core, the groove is easily formed on the outer peripheral surface of the movable core. The electromagnetic drive unit can be easily reduced in size (claim 3).
According to the electromagnetic valve device of the present invention, since the electromagnetic drive unit described above is provided, the electromagnetic valve device itself can be downsized. In addition, since the valve element is operated by the operating rod, the electromagnetic valve device operates stably over a long period of time with little variation in characteristics.

It is a longitudinal cross-sectional view of the solenoid valve apparatus of one Example of this invention, Comprising: The time at the time of the no electric power feeding to a solenoid is shown. It is a longitudinal cross-sectional view of the solenoid valve apparatus of FIG. 1, Comprising: The time of electric power feeding to a solenoid is shown. It is a perspective view of the movable iron core used for the solenoid valve device of FIG. It is a perspective view of the modification of the movable iron core of FIG. It is a perspective view of the other modification of the movable iron core of FIG.

Explanation of symbols

12 Valve unit (valve)
14 Drive unit 22 Fixed iron core 34 Solenoid assembly 38 Solenoid 72 Movable iron core 74 Resin layer 76 Axial groove (groove)
78 Oil chamber 80 Oil chamber 82 Axial hole 84 Rod (operation rod)
90 Valve spool (valve)

Claims (4)

A fixed iron core,
A movable iron core that is arranged slidably on the same axis with respect to the fixed iron core, and that divides oil chambers to which lubricating oil is supplied at both ends,
A solenoid assembly that encloses the movable iron core and operates the movable iron core by controlling power supply to the solenoid;
A nonmagnetic resin layer covering the outer peripheral surface of the movable iron core;
A groove formed in the resin layer and communicating between the oil chambers on both sides of the movable iron core;
An electromagnetic drive unit, comprising: an operating rod that is press-fitted into the movable iron core and moves integrally with the movable iron core. The electromagnetic drive unit according to claim 1, wherein the resin layer further includes a circumferential groove along a circumferential direction of the movable iron core. The electromagnetic drive unit according to claim 1, wherein the groove is formed by applying a resin material to an outer peripheral surface of the masked movable iron core. An electromagnetic drive unit according to any one of claims 1 to 3,
An electromagnetic valve device comprising: a valve body operated by the operation rod; and a valve that is switched in response to the operation of the movable iron core.

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